Andy,
Just curious - What is the volt-per-mil rating of the material
in between the traces supposed to be?
Doug
Dill, Norm J wrote:
>
> Andy,
> Considering your test was run at 100 v with a .006" spacing, is there
> any chance that airborne contaminants contributed to your 300/500 hour
> failures?
>
> Norm Dill
> [log in to unmask]
> ------------------------
> Subject: Re[2]: Humidity Testing
> Date: Wednesday, July 10, 1996 4:18PM
>
> We've done some testing on flex circuits and found that
> there was about a 300 hour incubation period before visible
> defects were evident on the failing circuits. Actual
> electrical failures (shorting) took up to 500 hours. The
> insulation resistance falls off early in the test as the
> moisture reaches equilibrium in the polyimide, and then
> falls further at about the time of the incubation period.
>
> The continuous bias voltage was 100V. 85C, 85%RH 100 mA
> current limited, 0.006" spaces between traces. Measurements
> were taken at 24, 48, 72, 144, 200, 300, 400, 500, 550 and
> 1500 hours.
>
> Andy Magee - Applications Engineer
> Rogers Corp - Circuit Materials Unit
> Tel: (602) 917-5237
> Fax: (602) 917-5256
> E-Mail: [log in to unmask]
>
> ______________________________ Reply Separator
> _________________________________
>
> Subject: Re: Humidity Testing
> Author: SIRGuru::(SIRGUR) at ~FABRIK
> Date: 7/10/96 1:12 PM
>
> From: [log in to unmask]
> Date: Wed, Jul 10, 1996 1:12 PM
> Subject: Re: Humidity Testing
> To: TechNet
> I'll give you my favorite engineering answer - It depends.
>
> If you are trying to determine if a fabrication or assembly process
> is
> Bellcore-compliant, the answer is no. Bellcore compliancy is only
> obtained
> through the SIR and Electromigration testing in Chapter 13 of TR-78.
>
> If you are trying to determine if a vendor has acceptable product,
> and you
> don't really care about Bellcore compliance, then I would say the
> answer is
> yes. The seven day SIR test, IPC-TM-650, method 2.6.3.3 rev A, is an
> alternative.
>
> The Bellcore electromigration test is 85C/85% RH, so is the SIR
> method.
> The Bellcore test goes 96 hours before the first measurement in an
> unbiased
> state, then a bias of 10 volts is applied.
> The SIR test is biased from the start with a 50 volt bias.
> The Bellcore test is not tied to an absolute resistance value.
> The SIR test has a minimum of 100 megohms.
>
> I'm not really trying to bash the Bellcore electromigration test, but
> I
> understand the time constraint. In my opinion (that and 50 cents
> gets you a
> Diet Coke), you are best to do both methods concurrently. The SIR
> test should
> be able to allow you to make the decision in 7 days vs. 25 days.
> Alternatively, you could interrupt the electromigration test after
> 7-10 days
> and see if you have any signs of corrosion or metal migration. It
> has been
> my experience that if you have not seen electromigration and
> corrosion after
> 7 days at 85/85 and a 50 volt bias, you would not see it in 500
> hours.
> Again, my opinion.
>
> Hope this was helpful. If you want to discuss it in greater depth,
> give me a
> call at (317) 457-8095.
>
> Doug Pauls
> CSL, Inc.
> [log in to unmask]
>
> **********************************************************************
> *****
> * TechNet mail list is provided as a service by IPC using SmartList
> v3.05 *
> **********************************************************************
> *****
> * To unsubscribe from this list at any time, send a message to:
> *
> * [log in to unmask] with <subject: unsubscribe> and no text.
> *
> **********************************************************************
> *****
>
> ----------
> Received: from spork.callamer.com by portia.fabrik.com
> with SMTP (Fabrik F05.4-000)
> id [log in to unmask] ; Wed, 10 Jul 1996 15:10:25
> -0800
> Received: from simon.ipc.org (IPC.ORG [168.113.24.64]) by
> spork.callamer.com (8.
>
> 7.5/8.7.3) with SMTP id PAA11863; Wed, 10 Jul 1996 15:07:10 -0700
> (PDT)
> Received: from ipc.org by simon.ipc.org via SMTP
> (940816.SGI.8.6.9/940406.SGI)
> id QAA04277; Wed, 10 Jul 1996 16:57:47 -0700
> Resent-Date: Wed, 10 Jul 1996 16:57:47 -0700
> Received: by ipc.org (Smail3.1.28.1 #2)
> id m0ue6Pj-0000KeC; Wed, 10 Jul 96 16:03 CDT
> Resent-Sender: [log in to unmask]
> Old-Return-Path: <[log in to unmask]>
> From: [log in to unmask]
> Date: Wed, 10 Jul 1996 17:12:07 -0400
> Message-ID: <[log in to unmask]>
> To: [log in to unmask]
> Subject: Re: Humidity Testing
> Resent-Message-ID: <"RJc9A2.0.AdK.9g1vn"@ipc>
> Resent-From: [log in to unmask]
> X-Mailing-List: <[log in to unmask]> archive/latest/5067
> X-Loop: [log in to unmask]
> Precedence: list
> Resent-Sender: [log in to unmask]
>
> ----------
>
> ***************************************************************************
> * TechNet mail list is provided as a service by IPC using SmartList v3.05 *
> ***************************************************************************
> * To unsubscribe from this list at any time, send a message to: *
> * [log in to unmask] with <subject: unsubscribe> and no text. *
> ***************************************************************************
>
> ***************************************************************************
> * TechNet mail list is provided as a service by IPC using SmartList v3.05 *
> ***************************************************************************
> * To unsubscribe from this list at any time, send a message to: *
> * [log in to unmask] with <subject: unsubscribe> and no text. *
> ***************************************************************************
***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To unsubscribe from this list at any time, send a message to: *
* [log in to unmask] with <subject: unsubscribe> and no text. *
***************************************************************************
|
